US2031368A

US2031368A - Method of lubrication and lubricant therefor

Info

Publication number: US2031368A
Application number: US719407A
Authority: US
Inventors: Walter D Hodson
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-04-06
Filing date: 1934-04-06
Publication date: 1936-02-18
Anticipated expiration: 1953-02-18

Description

-. Walter ill. Hudson, @hicago, llll:

No Drawing. Application April 6, 19%, Serial No. 719,407

7 v Claims.

This invention relates to a method of lubrication, particularly for roll necks in rolling mills,-

tion of such machinery has been extremely inemcient, and any attempt at emciency has m suited in the wastage of enormous quantities of lubricant.

It has been heretofore considered impossible to make the greases softer, since for a particular lubrication, a grease of definite hardness is required to stand the particular load and conditions. Non-lubricating material such as a high melt point asphalt is required on account oi the high temperature conditions. The greases used for this type of work have been soda or soda lime soap base greases, but it has heretofore not been possible to use large amounts of grease material.

In accordance with this invention, such greases are rendered more fluid by the incorporation of certain organic solvents, to such a point that they may be applied readily to the spot to be lubricated, for example, through an autotic or pressure lubrication system. The solvent is preferably so chosen that when the grease reaches the point of lubrication, the temperature present will cause the solvent to evaporate, and the grease will then regain its former characteristics.

The solvent chosen must be one which does not a cause a breakdown of the grease initially, or materially affect its lubricating properties, and should have a boiling point above normal atospheric conditions.

Clearly the solvent should not evaporate under the pressure and temperature conditions in the lubricant-feeding mechanism, but should have a simciently highboiling point as to maintain the necessary fluidity until the point of lubrication has been reached.

For example, a sodium base grease may be prepared in the orry manner containing to 50% of a soda soap, such as oleate, stearate or the like (preferably tallow fat acids), and the balance mineral oil of the desired viscosity. A typical grease will contain 30% sodium soap and Wu; of a vy i, i ed cylinder stock lJt ilfll eral oil having a viscosity of 200 Sayboldt at 210 F. Such a grease will be extremely hard. The proportion of tallow or soap is far higher in these greases than was possible under prior practice, and the greases therefore have a considerably higher melting point initially than for- Qmerly was the case for similar operating conditions.

The fluidity of such hard grease may then be modified by incorporating a solvent which will not destroy t e grease structure. For example, butyl carbitol, (monobutyl ether of diethylene glycol), carbitol, (monoethyl ether of diethylene glycol), ethylene dichloride, or dichlorethyl ether may be used, preferably in proportions of from 1% upwards. Normally not more than 5% need be used. With the particular sodium soap described, 2 of butyl carbitol is preferred. The addition of this amount of solvent renders the grease soft enough to be applied by ordinary mechanical lubrication methods, but does not afiect its lubricating properties.

By proper choice of solvents, one may be selected which will evaporate under the particular bearing temperature encountered, and will thus produce a grease having the original consistency and other characteristics of the initial product. For high temperature lubrication, butyl carbitol, having a boiling point of 431 F. is preferable. The carbitol boils at 388 F., the dichlorethyl ether at 350 F., and the ethylene dichloride at 188 F. and these solvents may be used for conditions suitable to their particular boiling points.

Upon reaching the point of lubrication, the solvent evaporates and produces. a grease of the original consistency. However, even if the solvent does not evaporate, the efiectiveness of the grease is not substantially impaired.

In the case of a lime soap grease, either an anhydrous or a hydrated grease may be used. In the case oi the anhydrous grease, a coupler should be used such as described in my co-pending application Serial No. 412,930.- The grease in general will contain 5 to 50% of a lime soap such as lime tallow soap, and the remainder consists of a mineral oil. For example, a hard grease may be prepared from lime tallow soap and 80% or a heavy mineral oil such as was described in connection with the soda soap grease. With this grease may be incorporated a small amount oi a coupler to prevent segregation, and the fluidity of the grease may then be modified as desired by incorporation of a minor percentage of a solvent such as a phenyl chloride, including monocr 1-1.4 w ortho dichior z:

iii

trichlor benzene, or solvents such as ethylene dichloride, dichlorethyl ether, trichlor ethylene or the like. 1 to 5% is normally suflicient, and 2 of monochlor benzene is preferred in the specific grease described.

As with the soda soap, the particular solvent may be chosen in accordance with the temperature to be encountered. Ethylene dichloride has a boiling point of 188 F; dichlorethyl ether of 350 F; ortho dichlor benzene of 354 F., monochlor benzene of 270 F., and trichlor benzene of 419 F. and trichlor ethylene of 188 F.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, but the appended claims should be construed as broadly as permissible, in view of the prior art.

I claim:

1. The method of lubricating a hot roll neck bearing normally requiring lubricating greases which are hard at atmospheric temperatures, which comprises adding to such a hard grease a small proportion of a grease compatible solvent volatile at the operating temperature of the bearing, said solvent being a hydrocarbon or derivative thereof and having a boiling point high enough that it does not evaporate under the temperature and pressure conditions of the lubricant feeding mechanism, the proportion of the solvent being large enough to soften the grease sufliciently to be applied by mechanical lubrication systems and being small enough that the grease structure is retained in the softened grease, and mechanically applying the grease to the bearing, where the heat of operation of the bearing evaporates the solvent and produces a grease inherently of the original consistency.

2. The method as set forth in claim 1, in which the solvent has a boiling point of at least 180 F.

3. The method as set forth in claim 1, in which the solvent is of the order of 1-5% of the lubricant.

4. The method as set forth in claim 1, in which the grease is a soda soap grease and the solvent is selected from the class consisting of monobutyl ethyl of diethylene glycol, monoethyl ether of diethylene glycol, ethylene dichloride and dichlorethyl ether.

5. The method as set forth in claim 1, in which the grease is a lime soap grease and the'solvent is selected from the class consisting of phenyl chlorides, ethylene. dichloride, trichlor ethylene, and dichlorethyl ether.

WALTER D. HODSON.